Dorado HV, Page 1
Part No. 01-001 Rev. 4.0051404
WWW.GALAXYPWR.COM
Suitable for Fan Motor Control
Industry Standard Quarter Brick
Pinout and Footprint
Typical Efficiency: 87% at 3A, 34V
Droop Feature Allows Current Sharing
Very Low Common-mode Noise for
a Commercial DC/DC Converter
Two-stage Input Filter
Constant Switching Frequency
Remote Sense
Single Board Design
Optional Low Profile Heatsink for
Improved Thermal Performance
Header with M3 Metal Inserts for
Mechanical Connection to PCB
Two Year Warranty
DORADO HV
Control Functions
Compatible with Fan Turn-on Requirements
Designed to be Stable with High Capacitance Load
Uses Innovative Control and Power Topology
for Lower Parts Count
Microprocessor Controlled
Primary-side Enable, Choice of Logic
Protection Features
Over Temperature Protection
Over Voltage Protection
Over Current Protection
Over/Under Input Voltage Protection
Typical Characteristics
Output Setpoint Accuracy:
0.2%
Load Regulation: +2% no load; -2% full load*
Line Regulation:
0.2%
Low Output Ripple
Output Trim
* Varies with setpoint and trim method.
The Dorado HV is also available with an optional
low profile heatsink for improved thermal
performance.
ISO 9001 CERTIFIED ORGANISATION
High-efficiency DC/DC Converter
48V Input, 18V to 34VDC Output, 3A Output
Dorado HV, Page 2
Part No. 01-001-C Rev. 4.0051404
WWW.GALAXYPWR.COM
General Specifications
Operating Temperature
-40
C to +100C
Storage Temperature
-55
C to +125C
Relative Humidity
10% to 95% RH,
Non-condensing
Vibration
2 to 9Hz, 3mm disp.,
9 to 200Hz 1g
Material Flammability
UL V-0
Weight
35 grams
MTBF
Telcordia (Bellcore)
1,600,000 hours
General Specifications
V
IN
= 48V
DC
, T
A
@25
C, 300 LFM Airflow, V
OUT
= 34V, I
OUT
= 1.5A. 68
F electrolytic capacitor across output pins.
Available output power depends on ambient temperature and good thermal management. (See application graphs for limits.)
Input Characteristics
Parameter
Min
Typ
Max
Units
Operating Input Voltage
36
48
75
V
DC
Input Current
4
A
Input Capacitance
2
F
Input Hysteresis, Low Line
2
V
DC
Output Characteristics
Output Voltage/Trim Range
17
34
V
DC
Regulation Over Line, Load & Temperature
97
103
%V
NOM
Voltage Ripple
30
mV
RMS
Current Range
0
3
A
Current Limit Inception
*
3.25
5.5
A
Turn-on Time to 98%Vnom
400
mS
Output Overshoot at Turn-on
1
%V
OUT
Overvoltage Protection
37
39
V
DC
Isolation
Isolation Test Voltage, Input/Output (Basic)
2000
V
DC
Isolation Resistance
10
M
Features
Overtemperature Protection, Thermal Sensor
**
117
C
Switching Frequency, Fixed
333
kHz
* Current limit inception is output voltage dependent. See Current Limit Graph on page 5.
** PCB less than 130
C
Approvals and Standards
UL and c-UL Recognized Component, TUV,
UL60950, CSA 22.2 No. 950, IEC/EN 60950**
EMC Characteristics:
Designed to meet emission and immunity
requirements per EN55022, CISPR 22, Class B,
and CISPR 24.
** An external fuse shall be used to comply with the
requirements.
Dorado HV, Page 3
Part No. 01-001 Rev. 4.0051404
WWW.GALAXYPWR.COM
Undervoltage Lockout
30
32
36
34
40
38
Input Voltage (V)
Input Curr
ent
Voltage
Rising
Voltage
Falling
Overvoltage Lockout
75
76
78
77
80
79
Input Voltage (V)
Input Curr
ent
Voltage
Rising
Voltage
Falling
CoolConverter
TM
Galaxy's proprietary CoolConverter
TM
provides:
Patented single-stage power conversion architecture,
control, and magnetic design allow unprecedented power
density and efficiency in an isolated power supply.
An advanced microcontroller reduces parts count while
adding features, performance, and flexibility in the design.
Low common-mode noise as a result of lower capacitance
in the transformer compared to planar magnetics and
metal baseplate designs.
Higher reliability than planar transformer designs that can
suffer from via fatigue from thermal cycling, and metal
baseplate designs with board to board interconnects that
are subject to mechanical stress on electrical connections.
Protection and Control
Valid Input Voltage Range:
The converter measures the input voltage and will not
allow operation outside of the input voltage
specification. As shown by the graphs, hysteresis is
added to both the high and low voltage to prevent the
converter from turning on and off repeatedly when the
voltage is held near either voltage extreme. At low line
this assures the maximum input current is not exceeded;
at high line this assures the semiconductor devices in
the converter are not damaged by excessive voltage
stress.
ON/OFF Logic Option:
The ON/OFF control logic can be either Negative
(standard) or Positive to enable the converter. For
Negative logic, the ON/OFF pin is brought below 1.0 V
with respect to the INPUT pin to enable the converter.
The pull-down must be able to sink 100
A. For
Positive logic, the ON/OFF pin is brought to greater
than 4.0 V with respect to the INPUT and be limited to
less than 10V. To request the Positive logic version,
add the suffix (P) to the standard part number. The ON/
OFF pin has a built-in pull up resistor of approximately
100 k
to +5V.
Application Notes
Dorado HV, Page 4
Part No. 01-001-C Rev. 4.0051404
WWW.GALAXYPWR.COM
Resistor
Output Over Voltage Protection:
The output voltage is monitored by a redundant
secondary-side circuit. If the output voltage exceeds the
over-voltage specification, the microprocessor will
restart every 2 seconds and limit voltage with a separate
reference circuit. This advanced feature prevents the
converter from damaging the load if there is a converter
failure or application error.
Latching is available as an option.
Over Current Protection:
If overcurrent lasts more than 3 seconds the converter
will shut down and try to restart every 10 seconds until
the fault is removed.
Latching is available as an option.
Thermal Shutdown:
The printed circuit board temperature is measured
using a semiconductor sensor. If the maximum rated
temperature is exceeded, the converter is turned off. It
will then restart every 2 seconds.
Latching is available as an option.
Remote Sense:
The output voltage is regulated at the point where the
sense pins connect to the power output pins. Total sense
compensation should not exceed 1V. A negative sense
lead is connected internally.
Safety:
An external input fuse must always be used to meet
these safety requirements.
Application Notes
Trim
Sense
R
TRIM
Resistor across Trim Pin
(Droop Percentage = 3%)
40
35
30
25
20
15
0
10
1000
100
Trim Pin to -Sense Resistance (kOhm)
Output V
oltage (V)
Vout Nom (0A)
Vout Nom (3A)
External Output Trimming
Dorado HV, Page 5
Part No. 01-001 Rev. 4.0051404
WWW.GALAXYPWR.COM
Dorado HV Operation
Efficiency
92
90
88
86
84
82
80
78
76
74
0
1.0
2.0
3.0
2.5
Output Current (A)
Ef
ficiency (%)
36V Vin
48V Vin
75V Vin
1.5
0.5
Current Limit Vs. Line/Trim Voltage
5.4
5.2
5.0
4.8
4.6
4.4
4.2
4.0
3.8
18
24
20
22
26
30
32
28
34
Trimmed Output Voltage (V)
Curr
ent Limit (A)
75V
60V
48V
36V
Power Dissipation Vs Line/Load
18
16
14
12
10
8
6
4
2
0
0
1.0
2.0
25
3.0
.
Output Current (A)
Power Dissipation (W)
36V Vin
48V Vin
75V Vin
0.5
1.5
2
1
Ch1
10.0V
Ch2
5.00 V
M 40.0ms A
Ch1
2.70V
T
T
[
]
Voltage Ripple
V
OUT
Setpoint Vs Line/Load
35.5
35.0
34.5
34.0
33.5
33.0
32.5
0
1.0
2.0
25
3.0
.
Output Current (A)
Output V
oltage (V)
36V Vin
48V Vin
75V Vin
0.5
1.5
Note: 68
F electrolytic capacitor across output pins for all graphs.
Startup
START
STOP
A/DIV
B/DIV
10.00 dB
36.00 deg
100.000
100 000.000
Hz
Hz
A T/R (dB)
A MAX
B MAX
B:
50.00
180.0
dB
deg
MKR
GAIN
PHASE
10.964.782
4.31822
107.062
Hz
mdB
deg
Bode Plot
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